Android网络开发之OkHttp--基本用法POST

1、OkHttp框架使用了OkIo框架，不要忘记下OkIo.jar

2、通过POST访问网络，和通过GET访问网络基本相同，多了设置请求参数的过程。主要分为五步：

(1)、声明并实例化一个OkHttpClient对象

(2)、声明并实例化一个RequestBody对象

(3)、声明并实例化一个Request对象

(4)、执行Request请求，并得到一个Response对象

(5)、根据Response的isSuccessful()方法判断是否成功，然后从Response对象中获取返回数据。

3、

public class PostActivity extends Activity {
private OkHttpClient client = new OkHttpClient();

private TextView mTvPost;

private String url = "https://www.baidu.com/";

private String result = "";

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_post);

initView();

new Thread(postThread).start();
}

public void initView(){
mTvPost = (TextView) findViewById(R.id.tv_post_show);
}

private Handler postHandler = new Handler(){
public void handleMessage(android.os.Message msg) {
mTvPost.setText(result);
};
};

private Thread postThread = new Thread(){
public void run() {
try {
run();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

postHandler.sendEmptyMessage(0);
};
};

/** Posting a String */
public static final MediaType jsonReq = MediaType.parse("application/json;charset=utf-8");

public void run() throws IOException {
RequestBody body = RequestBody.create(jsonReq, "{\"name\", \"name\"}");
Request request = new Request.Builder().url(url).post(body).build();
Response response = client.newCall(request).execute();
result += response.body().string();
}

/** Posting a File */
public static final MediaType MEDIA_TYPE_MARKDOWN1 = MediaType.parse("text/x-markdown;charset=utf-8");

public void run2() throws Exception {
File file = new File(Environment.getExternalStorageDirectory().getPath() + "/DCIM/Camera/IMG_20151030_205855.jpg");
Request request = new Request.Builder().url(url).post(RequestBody.create(MEDIA_TYPE_MARKDOWN, file)).build();
Response response = client.newCall(request).execute();
if (!response.isSuccessful()){
result += "出错" + response;
}else{
result += "没有出错" +response.body().string();
}
}

/** Posting from parameters */
public void run3() throws Exception {
RequestBody formBody = new FormEncodingBuilder().add("search","Jurassic Park").build();
Request request = new Request.Builder().url(url).post(formBody).build();
Response response = client.newCall(request).execute();

if (!response.isSuccessful()){
result += "出错了";
}else{
result += response.body().toString();
}
}

/** Posing Json with Gson */
private final Gson gson = new Gson();

public void run5() throws Exception {
Request request = new Request.Builder().url(url).build();
Response response = client.newCall(request).execute();
if (!response.isSuccessful()){
result += "出错了";
}else{
Gist gist = gson.fromJson(response.body().charStream(), Gist.class);
for (Map.Entry<String, GistFile> entry : gist.files.entrySet()) {
result += entry.getKey() + entry.getValue().content;
}
}
}

static class Gist {
Map<String, GistFile> files;
}

static class GistFile {
String content;
}

}

4、访问网络不能在主线程中进行，还有不要忘记加入访问网络的权限。

<uses-permission android:name="android.permission.INTERNET" />

5、对于Request对象是如何实例化的，大家可以参考--java builder模式
http://www.cnblogs.com/moonz-wu/archive/2011/01/11/1932473.html
6、参考博文：
http://www.2cto.com/kf/201505/397557.html